MRI can’t predict progression of common adolescent hip disorder

Here’s one indication for which MRI overutilization could stand to be curbed: predictive imaging of patients with slipped capital femoral epiphysis (SCFE), the most common hip disorder in adolescent boys (although girls can get it too).

Anders Wensaas, MD, of Akershus University in Norway and colleagues wanted to find out if MRI could predict future slippage of the contralateral (opposite-side) hip.

It’s an important question, as pre-symptomatic repair of SCFE is controversial: There’s no reliable method for predicting the onset of the disorder in the other, so-far-unaffected hip, so there’s no way to know when prophylactic interventions are truly necessary.

The researchers looked at 22 patients with unilateral SCFE, all of whom underwent MRI of both hips before their corrective intervention.

The team measured six parameters on MRI, including slip angle, widening of the physis (aka “growth plate”), bone marrow edema, pathological joint effusion and others over a mean follow-up period of 33 months.

Six patients were treated for contralateral slip during the follow-up time. To see if it was possible to predict subsequent contralateral slip at primary diagnosis, the researchers compared the MRI parameters of the contralateral hip in these six patients with those of the 16 patients who remained unilateral.

They found all MRI parameters were significantly altered in hips with established SCFE compared with the contralateral hips.

However, none of the MRI parameters “showed any significant difference between patients who had a subsequent contralateral slip and those that remained unilateral,” the authors write.